class Student(object):
    count = 0

    def __init__(self, name, age):
        self.name = name
        self.age = age
        Student.count += 1

    def mation(self):
        print('姓名是：{}，年龄是：{}'.format(self.name, self.age))

'''测试'''
xiao_liu = Student('xiao_liu', 18)
xiao_liu.mation()
print(Student.count)

xiao_bai = Student('xiao_bai', 20)
xiao_bai.mation()
print(Student.count)
print(Student.count)
xiao_wang = Student('xiao_wang', 20)
xiao_wang.mation()
print(Student.count)